| Step | Hyp | Ref
 | Expression | 
| 1 |   | f1ocnv 5300 | 
. . . 4
⊢ (H:A–1-1-onto→B →
◡H:B–1-1-onto→A) | 
| 2 | 1 | adantr 451 | 
. . 3
⊢ ((H:A–1-1-onto→B ∧ ∀x ∈ A ∀y ∈ A (xRy ↔
(H ‘x)S(H ‘y)))
→ ◡H:B–1-1-onto→A) | 
| 3 |   | f1ocnvfv2 5478 | 
. . . . . . . 8
⊢ ((H:A–1-1-onto→B ∧ z ∈ B) →
(H ‘(◡H
‘z)) = z) | 
| 4 | 3 | adantrr 697 | 
. . . . . . 7
⊢ ((H:A–1-1-onto→B ∧ (z ∈ B ∧ w ∈ B)) →
(H ‘(◡H
‘z)) = z) | 
| 5 |   | f1ocnvfv2 5478 | 
. . . . . . . 8
⊢ ((H:A–1-1-onto→B ∧ w ∈ B) →
(H ‘(◡H
‘w)) = w) | 
| 6 | 5 | adantrl 696 | 
. . . . . . 7
⊢ ((H:A–1-1-onto→B ∧ (z ∈ B ∧ w ∈ B)) →
(H ‘(◡H
‘w)) = w) | 
| 7 | 4, 6 | breq12d 4653 | 
. . . . . 6
⊢ ((H:A–1-1-onto→B ∧ (z ∈ B ∧ w ∈ B)) →
((H ‘(◡H
‘z))S(H
‘(◡H ‘w))
↔ zSw)) | 
| 8 | 7 | adantlr 695 | 
. . . . 5
⊢ (((H:A–1-1-onto→B ∧ ∀x ∈ A ∀y ∈ A (xRy ↔
(H ‘x)S(H ‘y)))
∧ (z ∈ B ∧ w ∈ B)) →
((H ‘(◡H
‘z))S(H
‘(◡H ‘w))
↔ zSw)) | 
| 9 |   | f1of 5288 | 
. . . . . . 7
⊢ (◡H:B–1-1-onto→A →
◡H:B–→A) | 
| 10 | 1, 9 | syl 15 | 
. . . . . 6
⊢ (H:A–1-1-onto→B →
◡H:B–→A) | 
| 11 |   | ffvelrn 5416 | 
. . . . . . . . 9
⊢ ((◡H:B–→A
∧ z ∈ B) →
(◡H
‘z) ∈ A) | 
| 12 |   | ffvelrn 5416 | 
. . . . . . . . 9
⊢ ((◡H:B–→A
∧ w ∈ B) →
(◡H
‘w) ∈ A) | 
| 13 | 11, 12 | anim12dan 810 | 
. . . . . . . 8
⊢ ((◡H:B–→A
∧ (z ∈ B ∧ w ∈ B)) →
((◡H ‘z)
∈ A ∧ (◡H ‘w)
∈ A)) | 
| 14 |   | breq1 4643 | 
. . . . . . . . . . 11
⊢ (x = (◡H
‘z) → (xRy ↔ (◡H
‘z)Ry)) | 
| 15 |   | fveq2 5329 | 
. . . . . . . . . . . 12
⊢ (x = (◡H
‘z) → (H ‘x) =
(H ‘(◡H
‘z))) | 
| 16 | 15 | breq1d 4650 | 
. . . . . . . . . . 11
⊢ (x = (◡H
‘z) → ((H ‘x)S(H ‘y)
↔ (H ‘(◡H
‘z))S(H
‘y))) | 
| 17 | 14, 16 | bibi12d 312 | 
. . . . . . . . . 10
⊢ (x = (◡H
‘z) → ((xRy ↔ (H
‘x)S(H
‘y)) ↔ ((◡H
‘z)Ry ↔
(H ‘(◡H
‘z))S(H
‘y)))) | 
| 18 |   | bicom 191 | 
. . . . . . . . . 10
⊢ (((◡H
‘z)Ry ↔
(H ‘(◡H
‘z))S(H
‘y)) ↔ ((H ‘(◡H
‘z))S(H
‘y) ↔ (◡H
‘z)Ry)) | 
| 19 | 17, 18 | syl6bb 252 | 
. . . . . . . . 9
⊢ (x = (◡H
‘z) → ((xRy ↔ (H
‘x)S(H
‘y)) ↔ ((H ‘(◡H
‘z))S(H
‘y) ↔ (◡H
‘z)Ry))) | 
| 20 |   | fveq2 5329 | 
. . . . . . . . . . 11
⊢ (y = (◡H
‘w) → (H ‘y) =
(H ‘(◡H
‘w))) | 
| 21 | 20 | breq2d 4652 | 
. . . . . . . . . 10
⊢ (y = (◡H
‘w) → ((H ‘(◡H
‘z))S(H
‘y) ↔ (H ‘(◡H
‘z))S(H
‘(◡H ‘w)))) | 
| 22 |   | breq2 4644 | 
. . . . . . . . . 10
⊢ (y = (◡H
‘w) → ((◡H
‘z)Ry ↔ (◡H
‘z)R(◡H ‘w))) | 
| 23 | 21, 22 | bibi12d 312 | 
. . . . . . . . 9
⊢ (y = (◡H
‘w) → (((H ‘(◡H
‘z))S(H
‘y) ↔ (◡H
‘z)Ry) ↔
((H ‘(◡H
‘z))S(H
‘(◡H ‘w))
↔ (◡H ‘z)R(◡H
‘w)))) | 
| 24 | 19, 23 | rspc2va 2963 | 
. . . . . . . 8
⊢ ((((◡H
‘z) ∈ A ∧ (◡H ‘w)
∈ A)
∧ ∀x ∈ A ∀y ∈ A (xRy ↔ (H
‘x)S(H
‘y))) → ((H ‘(◡H
‘z))S(H
‘(◡H ‘w))
↔ (◡H ‘z)R(◡H
‘w))) | 
| 25 | 13, 24 | sylan 457 | 
. . . . . . 7
⊢ (((◡H:B–→A
∧ (z ∈ B ∧ w ∈ B)) ∧ ∀x ∈ A ∀y ∈ A (xRy ↔
(H ‘x)S(H ‘y)))
→ ((H ‘(◡H
‘z))S(H
‘(◡H ‘w))
↔ (◡H ‘z)R(◡H
‘w))) | 
| 26 | 25 | an32s 779 | 
. . . . . 6
⊢ (((◡H:B–→A
∧ ∀x ∈ A ∀y ∈ A (xRy ↔ (H
‘x)S(H
‘y))) ∧ (z ∈ B ∧ w ∈ B)) →
((H ‘(◡H
‘z))S(H
‘(◡H ‘w))
↔ (◡H ‘z)R(◡H
‘w))) | 
| 27 | 10, 26 | sylanl1 631 | 
. . . . 5
⊢ (((H:A–1-1-onto→B ∧ ∀x ∈ A ∀y ∈ A (xRy ↔
(H ‘x)S(H ‘y)))
∧ (z ∈ B ∧ w ∈ B)) →
((H ‘(◡H
‘z))S(H
‘(◡H ‘w))
↔ (◡H ‘z)R(◡H
‘w))) | 
| 28 | 8, 27 | bitr3d 246 | 
. . . 4
⊢ (((H:A–1-1-onto→B ∧ ∀x ∈ A ∀y ∈ A (xRy ↔
(H ‘x)S(H ‘y)))
∧ (z ∈ B ∧ w ∈ B)) →
(zSw ↔ (◡H
‘z)R(◡H ‘w))) | 
| 29 | 28 | ralrimivva 2707 | 
. . 3
⊢ ((H:A–1-1-onto→B ∧ ∀x ∈ A ∀y ∈ A (xRy ↔
(H ‘x)S(H ‘y)))
→ ∀z ∈ B ∀w ∈ B (zSw ↔ (◡H
‘z)R(◡H ‘w))) | 
| 30 | 2, 29 | jca 518 | 
. 2
⊢ ((H:A–1-1-onto→B ∧ ∀x ∈ A ∀y ∈ A (xRy ↔
(H ‘x)S(H ‘y)))
→ (◡H:B–1-1-onto→A ∧ ∀z ∈ B ∀w ∈ B (zSw ↔ (◡H
‘z)R(◡H ‘w)))) | 
| 31 |   | df-iso 4797 | 
. 2
⊢ (H Isom R,
S (A,
B) ↔ (H:A–1-1-onto→B ∧ ∀x ∈ A ∀y ∈ A (xRy ↔
(H ‘x)S(H ‘y)))) | 
| 32 |   | df-iso 4797 | 
. 2
⊢ (◡H Isom
S, R
(B, A)
↔ (◡H:B–1-1-onto→A ∧ ∀z ∈ B ∀w ∈ B (zSw ↔ (◡H
‘z)R(◡H ‘w)))) | 
| 33 | 30, 31, 32 | 3imtr4i 257 | 
1
⊢ (H Isom R,
S (A,
B) → ◡H Isom
S, R
(B, A)) |